The 57-year-old actress portrays a high-ranking CEO in the new erotic thriller film, but Nicole feels hesitant about watching the movie at the premiere in Venice.
The Oscar-winning actress - who stars alongside Harris Dickinson, Sophie Wilde and Antonio Banderas in the film - told Vanity Fair magazine: "There's something in me going: 'Okay, this was made for the big screen and to be seen with people.' I'm not sure I have that much bravery."
Nicole acknowledged that 'Babygirl' is the most "exposing" film of her career.
She shared: "I've made some films that are pretty exposing, but not like this."
Nicole feels particularly anxious about her sex scenes.
The Hollywood star explained: "It's like, golly, I'm doing this, and it's actually now going to be seen by the world. That's a very weird feeling."
Earlier this year, Nicole played Zac Efron's on-screen love interest in 'A Family Affair', and the actress previously admitted that she considered the script to be a breath of fresh air.
Nicole also relished the experience of working with Zac, 36, on the movie.
Nicole - who is married to music star Keith Urban - told PEOPLE: "We've had it from way back with older men and younger women, that's just always been the norm - it's okay, it's completely acceptable. The problem is we've not had the equivalent from all different viewpoints, with women telling the stories. And we need game men.
"[Zac] came in and makes the film because he was like, 'I'm here to have fun, to play, and to very much be a part of this and be there for you.'"